Fred, you can stop scratching your head and furrowing your brows now as to whether the French handlebar makers CTA and ATAX were one and the same company; they were not.
Rather surprisingly the French cycling industry when at the height of its more recent production in the 50s to 70s was able to boast seven manufacturers of reasonable to good quality bars and stems and several more producers of cheaper mass-market varieties. The brands/makers were:
ATAX - see Philippe below AVA, based at Noyon in NE France BELLERI based at Sorbiers just outside St Etienne in the south CTA based at the oddly named Conches-en-Ouche in the NW GUID ( Ets R. Chalaye) based in St Etienne in the same building as CLB MAVIC based at St Trivier near Lyon Philippe ( marketed by ATAX) basred at Oullins in the southern suburbs of Lyon PIVO based at Montreuil in the eastern suburbs of Paris
As far as CTA were concerned, their product range was somewhat similar in intended destination as the products of Belleri - ie at best the sports, amateur course - mid-range bikes, although BELLERI did manufacture in the late 80s/early90s a range of superb stems and bars to match anything coming out of Italy, and under an English-sounding brand name..the project was very short lived...too little too late..
Other brand names such as MILREMO, JPR ( jean-Paul Routens) , RIGIDA surface from time to time. Milremo were produced by either ATAX or PIVO, JPR by Belleri ( I think) and RIGIDA was a sub-brand of ATAX. I suspect that MAVIC sub-contracted their bars to Belleri
As for CTA...I think it means Compagnie Technologie Aeronautique..OR Cintrage Tubes Acier..more research needed, I'm afraid.
Norris Lockley
Settle UK